1. Field of the Invention
The present invention relates to a light illuminating type manipulation and display apparatus which is mounted on, for example, a vehicle and the like, and more specifically, to a light illuminating type manipulation and display apparatus using a single light source.
2. Description of the Related Art
Ordinarily, when display panels are illuminated, it is sufficient to individually dispose light sources just below subjects to be illuminated such as, for example, indicator sections, display sections and the like. With this arrangement, however, the number of the light sources is increased, whereby power consumption as well as the number of parts are increased so that cost is made high and an assembling job becomes troublesome.
To cope with this problem, conventionally, vehicle-mounted light illuminating type manipulation and display apparatuses and the like comprise a lamp housing composed of a white molded body, a single light source inserted into the lamp housing, a rotary knob, which has a plurality of stop positions and an indicator section illuminated and displayed by with light from the light source. The light from the light source is reflected from the inner surface of the lamp housing and indicator section is illuminated and displayed with the reflected light.
With this arrangement, since the number of the lamp required is only one, power consumption is low and the number of parts is reduced as well as cost and the number of working processes are also decreased. However, this arrangement also has drawbacks.
That is, the rotary knob (indicator section) has a plurality of the stop positions some of which are located near to the light source and the others of which are located far therefrom. Further, an approximately constant quantity of light is reflected from the lamp housing. Thus, when the indicator section stops at a position relatively near to the light source, it is bright. However, when the indicator section is far from the light source, it is made dark, and this is undesirable from a quality standpoint.
To solve the above problem, it can be conceived to increase the illumination intensity of a light source itself. However, this solution has a drawback in that power consumption and the heating value generated by the light source are increased.